The present invention relates to a double-current detector, and more particularly to a double-current detector for shaping a double-current signal transmitted through a line of a data transmission system such as telex, for example.
Some conventional double-current detectors for producing a rectangular wave substantially in synchronism with a received double-current signal from a data transmission system include rheostats or variable resistors for adjusting positive and negataive slice levels employed by comparators which compare output signals from photocouplers with such slice levels. However, the use of such rheostats has been disadvantageous in that the cost of the double-current detectors is high, and slice level adjustments are necessary. Furthermore, characteristic variations of the photocouplers must be small.